<template>
  <div id="app">
    <el-button type="text" @click="centerDialogVisible = true">点击打开 Dialog</el-button>
    <el-dialog title="提示" :visible.sync="centerDialogVisible" width="30%" top="15vh" close="handleOpen" center >
      <span>需要注意的是内容是默认不居中的</span>
      <span slot="footer" class="dialog-footer">
        <el-button @click="centerDialogVisible = false">取 消</el-button>
        <el-button type="primary" @click="centerDialogVisible = false">确 定</el-button>
      </span>
    </el-dialog>
  </div>
</template>

<script>
export default {
  data() {
    return {
      centerDialogVisible: false
    };
  },
  methods: {
    handleOpen() {
      alert(123);
    }
  }
};
</script>

<style>
#app {
  font-family: "Avenir", Helvetica, Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-align: center;
  color: #2c3e50;
  margin-top: 60px;
}
</style>